如何从Firebase存储中删除照片

Question

我正在开发一个应用程序时，当用户可以登录，在用户配置文件页面中，用户可以在我的应用中选择一个图像配置文件。该图像在firebase数据库中上传，并存储在firebase存储中。我想让用户如果愿意，可以决定删除他当前的图像配置文件。我找不到方法，我如何从firebase存储中删除他的图像，我使用元数据将其放入存储中。

这是我的代码，用于在Firebase存储和Firebase数据库中上传图像：

// Create a path in order to save the photo in Firebase Database
func setUser(img: String) {
    var userUid = Auth.auth().currentUser?.uid
    let userData = ["nickname": Auth.auth().currentUser?.displayName, "userImg": img]
    KeychainWrapper.standard.set(userUid!, forKey: "uid")
    let location =                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Database.database().reference().child("users").child(userUid!).child("pseudo")
    location.setValue(userData)
    dismiss(animated: true, completion: nil)
}
// Upload and put image profile in the Firebase Storage
func uploadImg() {
    name = Auth.auth().currentUser?.displayName
    userUid = Auth.auth().currentUser?.uid
    guard let img = userImagePicker.image, imageSelected == true else {
        print("Image needs to be selected")
        return
    }
    if let imgData = UIImageJPEGRepresentation(img, 0.2) {
        let imgUid = NSUUID().uuidString
        let metadata = StorageMetadata()
        metadata.contentType = "image/jpeg"
        Storage.storage().reference().child(imgUid).putData(imgData, metadata: metadata) { (metadata, error) in
            if error != nil {
                print("Didn't upload image in Firebase Storage")
                self.isUploaded = false
            } else {
                print("Uploaded in Firebase Storage")
                self.isUploaded = true
                let downloadURL = metadata?.downloadURL()?.absoluteString
                if let url = downloadURL {
                    self.setUser(img: url)
                    self.downloadPhoto(user: self.name)
                }
            }
        }
    }
}
// The alert Controller (user can choose to take a photo with Camera or choose an image in his library then I use UIImagePickerController in order to display the image on a UIImageView)
@IBAction func actionButton(_ sender: Any) {
let attributedString = NSAttributedString(string: "User photo", attributes: [
    NSFontAttributeName : UIFont.boldSystemFont(ofSize: 15),
    NSForegroundColorAttributeName : UIColor.black
    ])
let alertController = UIAlertController(title: "", message: "", preferredStyle: .actionSheet)
alertController.message = nil
alertController.setValue(attributedString, forKey: "attributedTitle")
alertController.addAction(UIAlertAction(title: "Take photo", style: .default, handler: self.takePhoto))
alertController.addAction(UIAlertAction(title: "Choose in Library", style: .default, handler: self.libraryPhoto))
alertController.addAction(UIAlertAction(title: "Show current photo", style: .default, handler: self.showPhoto))
alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(alertController, animated: true, completion: nil)
}

如果添加一个"删除照片"，该如何删除此图像？如何在Firebase存储中检索此图像？我找不到正确的图像并删除它，我真的不知道如何在firebase存储中创建文件夹，因此所有用户图像都位于存储的同一部分，我无法检索右图像（imageuid）。

Answer 1

要删除图像，您需要能够重新创建图像的路径。这意味着知道图像的文件名。

目前保存图像时，您将每个人分配一个随机的UUID，并在存储桶的根部中chuck起来，从组织的角度来看，这无济于事。我会为每个用户创建一个文件夹并将图像存储为有用的东西（例如profilePic.jpg），如下：

func uploadImg() {
    name = Auth.auth().currentUser?.displayName
    userUid = Auth.auth().currentUser?.uid
    guard let img = userImagePicker.image, imageSelected == true else {
        print("Image needs to be selected")
        return
    }
    if let imgData = UIImageJPEGRepresentation(img, 0.2) {
        let metadata = StorageMetadata()
        metadata.contentType = "image/jpeg"
        // create reference to image location
        let profilePicRef = Storage.storage().reference().child("(userUid!)/profilePic.jpg")
        // upload image
        profilePicRef.putData(imgData, metadata: metadata) { (metadata, error) in
            if error != nil {
                print("Didn't upload image in Firebase Storage")
                self.isUploaded = false
            } else {
                print("Uploaded in Firebase Storage")
                self.isUploaded = true
                let downloadURL = metadata?.downloadURL()?.absoluteString
                if let url = downloadURL {
                    self.setUser(img: url)
                    self.downloadPhoto(user: self.name)
                }
            }
        }
    }
}

现在我们可以轻松找到配置文件图片，我们可以轻松地将其删除：

func deleteProfilePic() {
    guard let userUid = Auth.auth().currentUser.uid else {
        return
    }
    let pictureRef = Storage.storage().reference().child("(userUid)/profilePic.jpg")
    pictureRef.delete { error in
        if let error = error {
            // Uh-oh, an error occurred!
        } else {
            // File deleted successfully
        }
    }
}